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From: Josh Berkus <josh@agliodbs.com>
To: pgsql-performance@postgresql.org
Subject: Re: Performance question 83 GB Table 150 million rows, distinct select
Date: Wed, 16 Nov 2011 21:19:01 -0800
Message-ID: <4EC49945.40408@agliodbs.com> (raw)
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	<CAEaSS0Y2W=2h6aGj0eUnnjP7JnVUqtjj+7_mczQVBfGQ3L8ZGw@mail.gmail.com>

Tory,

A seq scan across 83GB in 4 minutes is pretty good.   That's over
300MB/s.  Even if you assume that 1/3 of the table was already cached,
that's still over 240mb/s.  Good disk array.

Either you need an index, or you need to not do this query at user
request time.  Or a LOT more RAM.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

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